Objective-C static, extern, public variables

Question

I want to have a variable that I can access anywhere by importing a header file but I also want it to be static in the sense that there is only one of them created. In my .

Answer 1

Separate global variable (one per source file):

// .h
static NSString * aStatic;

//.m
static NSString * aStatic = @"separate";

Unique global variable:

// .h
extern NSString * anExtern;

// .m
NSString * anExtern = @"global";